Question about the "germline gene usage" in the report

[NikaAb]

Hi @aluxsn, @DradjatKevin ! You have done a great job so far :) I was looking at your report here : https://github.com/julibinho/repDiversity/blob/main/documments/repports/Outils_projet.pdf In the ImmuneRef section, you have mentioned : "Nombre de gènes de lignée germinale dans chaque répertoire. Les gènes de lignée germinale (germline genes) sont défins dans la base de donnée International ImMunoGeneTics."

I wonder if this is a good translation for "germline gene usage". Since it can also be an unclear concept for you, would you please write down in 5 sentences at max, explaining your understanding about the "germline gene usage" in this context? It would be great if you say what are germline genes and why they can be used as a source of information for describing a repertoire.

Thanks !

[DradjatKevin]

Hello @NikaAb, from what i understood, germline gene usage is the frequency of V, D and J genes used in the VDJ recombination to form the B cell receptor. By calculating these frequencies, we can compare them to a normal frequencies distribution to determine if the repertoire belong to an ill person or not. We can also observe the evolution of the germline gene usage of a unique repertoire to study the impact of a vaccine per example. Did i misunderstood the concept ? I think the terms i chose for the translation are not suitable, i will modify this description on the next report.

[NikaAb]

Bravo @DradjatKevin ! It's great ! I know the names are sometimes confusing so we have "Germline" which translates to "lignée germinale" in french :

La lignée germinale est l'ensemble des cellules allant des cellules souches aux gamètes. On parle également des cellules germinales qui, contrairement aux cellules somatiques, transmettent à leur descendance (au cours de la reproduction sexuée) les mutations génétiques qu'elles auraient subies.

Here is what we can say about the Ig's genes :

Pour chacune de ces chaînes il existe plusieurs gènes V, plusieurs gènes J, plusieurs gènes D et plusieurs gènes C. Au niveau des précurseurs de la lignée B, ces gènes sont en configuration germinale, autrement dit ces gènes sont non fonctionnels étant éloignés les uns des autres sur les chromosomes.

And that's all!

Thanks :)